Cultivators are machines in the agriculture industry that are used to break up soil. They are pulled behind tractors using either a three-point linkage or a tractor drawbar. Cultivators are generally used before plows to till the soil and prepare it for the dispersing of seeds and can be used before and after the crops are sowed. They can provide other functions, such as removing and destroying weeds, as well as fertilizing the soil and covering seeds with soil.

Cultivators are very similar to harrows in their function but are generally used to work large clods of soil while harrows tend to be used afterwards to create finer tilth. While the terms cultivator and harrow are sometimes used interchangeably, cultivators are determined by their ability to penetrate large depths in order to sufficiently break up the soil for seedbed preparation.

Before there were cultivators, hoes or sticks were used to break up the soil. This arduous method was improved upon slightly with the development of the harrow. To make it easier to pull, the harrow was designed in a triangular shape and persisted until the 1850s when the first horse-drawn cultivator was made. It was used for very basic gardening and for cultivating corn stalks because corn crops were typically too high to cultivate. The one-horse cultivator consisted of as many as five teeth to comb the soil. The two-horse straddle-row cultivator was patented in 1856.[1]

As the agriculture industry grew, more manufacturers began producing cultivators during the 1880s. They expanded from one-row cultivators, to two-rows, riding cultivators, and shovel and straddle-row cultivators. One factor that played a salient role in the expansion of cultivators was the concept of planting seeds by row rather than broadcasting or scattering them randomly. This made it easier to dig out the vegetables when they had grown and the cultivator became a very efficient tool for doing this accurately and quickly.[2]

As well, the better that soil was crumbled, the more effective it would be in the growth of crops. Cultivators were so effective that they even began to replace harrows for bigger jobs during the late 18th century.[3]

Very little changed over time, with only small variations being added to the cultivator after the 1940s. Instead of using animals and horse shafts, cultivators used tractors and tractor drawbars. Additional changes included the power take-off and the concept of the three-point linkage system on farm tractors.

One of the standard prototypes of cultivators was the FergusonTE 20tractor which had implements for cultivating. The 1950s tractor that operated with hydraulic wheels could work at various depths if required. Tines or teeth were improved upon in the 1950s, with various types such as the spring tine, flexi-coil tine, and the spiked or rigid tine, all of which were used for various soil depths and applications.[4]

The cultivator has very basic features and components. It consists of various levers: spacing, tilthing, a master lever, and an independent depth lever. There is a main pivotal wheel used for altering the direction of the wheel, a foot pedal, a pin break, a roof shovel, and a bail rig hanger.

Cultivators are dragged behind tractors by either a three-point linkage or a tractor drawbar. They are pulled up the crop rows where the tines or teeth crumble soil at various depths and lengths. The tines are connected to a field shank. The tines or teeth (in their various shapes and sizes) till soil at designated depths and can also be used for removing unwanted weeds and rubbish.

The depth that the soil is tilthed can be controlled by the wheel, draught, or position control. The wheel control method is accomplished by setting how much weight will be transferred to the rear wheels of the tractor.

Draught control means that a hydraulic function on the three-point linkage is operated to control the amount of weight placed on the rear wheels of the tractor.

The position control works by setting the desired depth on a mechanical calculator that restricts the amount of hydraulic oil.[5]

Cultivators can come with attachments such as the stalk cutter, which is used to cultivate corn and cotton. The stalk cutter consists of a cylinder with five to nine knives that roll and cut stalks of corn or cotton at a particular length that ensures little or no disruption to the next round of crops.

Stalk hooks are another feature of cultivators—they are located in the front of the stalk cutter cylinder and grasp onto stalks. There are two types that do this. The first is the spiral knife cutter, which functions when the wheels are raised and the cylinder is lowered to the ground and cuts the stalks. The second type is the straight knife cutter, which also consists of a cylinder but has a frame mounted on top of it and uses spring pressure on the ground to cut the stalks. This type provides for a smoother operation.

Some cutters contain reversible knives that have corrugated edges that can also be used as a single- or double-row cultivator.[6]

Tines refer to the implements used to comb or till the soil and can come in various shapes and sizes. The spring-mounted tine cultivator is used for lighter soil applications. The steel spring tine is C-shaped and has pointed digging tips. This type of tine has a reverse bend at the end that is used for implementation onto the cultivator. Another type of spring tine is more square shaped and is used for deeper penetration.[7]

The S-tine, as the name implies, is S-shaped and is generally used to refine the tillage of the soil, the second or third time around. It can also be used for row crop cultivation and comes in sizes 1.25 to 1.77 inches (3.2 to 4.5 cm) wide by 0.4 to 0.5 inches (1.0 to 1.4 cm) thick. Tines are attached to a field shank on the cultivator, which is a cross section usually less than 0.75 inches (19 cm) thick.

Cultivators consist of several rows of tines, two or three of these rows are “staggered” to allow an equal amount of space between each tine for mixing the soil. Cultivators that have spring tines sometimes come with a device that permits the tines to penetrate the same depths and lengths of ground.[9]

Chisel plows can also accompany cultivators when the work requires a medium to heavy tillage.[10]

Cultivators can also be used to hoe row crops with special attachable blades that remove unwanted weed. Concave discs are added to the cultivator and allow the operator to determine the row widths at which to hoe the crop.[11]

This type of cultivator breaks up the soils using rotating tillers that slice through the ground. The rotary cultivator is connected to the tractor by the three-point linkage and uses the tractor’s power take-off to power the rotors in the same direction that the wheels rotate. The rotors are vertical which makes them efficient in preparing the seedbed.[12]

The field cultivator acts as a secondary tillage implement and can remove weeds as well as preparing the seedbed for crops. Field cultivators consist of spring tines made of steel. The shanks or teeth have little holes for shovel attachments. Teeth vary in widths, from 5.9 to nine inches (15 to 23 cm) and produce “staggering” patterns in the soil.

The row crop cultivator is also used as a secondary source of tillage and functions by tilling the soil in designated rows so as not to disturb them. Depth controlling wheels and shanks are features that control the depth of this type of cultivator.[13]

John Deere’s 2010 field cultivator and 960 field cultivator contain features such as a floating hitch wheel configuration, more precise and accurate depth control, a T-style hitch, and variety of sprays and teeth attachments.[14]

Wilrich’s DCIII disc cultivator has five-bar frame. Its notable features are the level-lift hitch with a screw attachment, a heavy-duty screw type jack, visual gauge of shank depth, and single point depth control of the hydraulics.[15]

Wilrich’s field cultivators such as the QX2 and the XL2 have the option of a floating hitch or level lift hitch respectively.[16]

The Case IH Tigermate II field cultivator has a mechanical depth control, walking tandems on the mainframe, and one-way pivoting stabilizing wheels.